1. Field of the Invention
The present invention relates to an automotive air conditioning system for use in an automobile having storage means, power generation means for charging the storage means, and air conditioning means having an electric compressor driven by feeding from the storage means.
2. Related Background Art
Conventionally, a car air-conditioner (air conditioning means) for use in a general automobile has had a compressor driven by a fuel engine (an internal combustion engine). High-temperature gas refrigerant, which has been discharged from the compressor and flowed into an exterior unit heat exchanger, radiates heat through heat exchanges with an air outside the passenger compartment caused by an exterior unit blower and is condensed to a liquid. Thereafter it flows into an interior unit heat exchanger arranged inside the passenger compartment via an expansion valve. The liquid refrigerant evaporates there and absorbs heat from circumambient air, thereby taking cooling action. This interior unit heat exchanger air-conditions by taking the heat out of the passenger compartment with heat exchanges to the air of the inside of the passenger compartment circulated by the interior unit blower. Then, refrigerant from the interior unit heat exchanger returns to the compressor and the refrigerating cycle is repeated.
This type of car air-conditioner is provided with a control unit, which turns off a rotation of the compressor when the passenger compartment is air-cooled up to the lower limit temperature among the given upper limit temperature and lower limit temperature set at the top and bottom of the preset temperatures. Then, if the inside temperature of the passenger compartment rises up and reaches the upper limit temperature, the control unit restarts air-cooling the passenger compartment by turning on the compressor. In this manner, the conventional system air-cools the passenger compartment, having a heating action from the heater added, thereby air-conditions the passenger compartment at a preset temperature at all seasons.
On the other hand, recently the development of electric vehicles has been accelerated by questions of the global environmental pollution problems caused by exhaust emission from those fuel engine vehicles. The electric vehicles include a pure electric vehicle (PEV) with a battery (in-vehicle battery) mounted on the automobile, which runs by driving a traveling motor powered by the in-vehicle battery, in addition to a series hybrid vehicle running with charging an in-vehicle battery using power generated by a fuel engine and with driving a traveling motor using power fed from the battery, a parallel hybrid vehicle running with cooperation between a traveling motor and a fuel engine, a series and parallel hybrid vehicle (HEV) having both functions of the series and parallel hybrid vehicles, and a fuel cell powered vehicle (FCEV) running with charging an in-vehicle battery using power generated by a fuel cell and with driving a traveling motor using power fed from the battery.
In air-conditioning a passenger compartment like the above in the electric vehicle, an electric compressor driven by feeding from the in-vehicle battery is used as a compressor for the air conditioning means (car air-conditioner). If the in-vehicle battery is discharged by power consumption in the electric compressor, however, it may cause such a problem that traveling itself is disrupted.
Also in a general fuel engine vehicle, an alternator driven by an engine generates power and the power is used for charging an in-vehicle battery. Therefore, if a compressor for air conditioning means is driven as an electric compressor by using the in-vehicle battery also in this case, a performance control (frequency control) of the compressor can be easily performed and more comfortable air conditioning in the passenger compartment can be achieved. Nevertheless, if the in-vehicle battery is discharged due to power consumption in the electric compressor, an engine control unit, a change gear control unit, and an igniter malfunction, thereby disrupting the traveling itself.
As a solution to these problems, there will be a way of increasing the capacities of the in-vehicle battery, the fuel engine, and the fuel cell up to the levels enough to cover the demand of the power consumption in the electric compressor. It, however, causes a steep rise in the cost and an increase in the weight of the automobile itself. Therefore, it rather causes a deterioration of its traveling performance itself or an increase of auto emission.
To solve these problems of the conventional art, the present invention is provided. Therefore, there is provided an automotive air conditioning system, which is free from troubles in traveling itself caused by power consumption in air conditioning means in an automobile having storage means, power generation means for charging the storage means, and air conditioning means having an electric compressor driven by feeding from the storage means.